This proposal is for continuing support of a project designed to evaluate the phenomenon of hormone resistance in depressive illness. Primary hormone resistance has been described for most peptide and steroid hormones, and in many cases is mediated by a receptor abnormality. While total resistance to cortisol would be lethal, there is precedent for receptor-mediated resistance in one family and in cultured leukemia and lymphoma cells. Study of receptor-mediated hormone resistance in depressive illness is limited by requirements for large amounts of tissue, by insensitive methods of receptor characterization, and by the low specific activity of available ligands. In this project, we propose to identify depressed patients with significant hypercortisolemia and to ascertain their degree of resistance to dexamethasone. Lymphocytes from these patients and control patients will be transformed by Epstein Barr virus to establish continuous tissue culture cell lines which will be used to prepare purified and partially purified glucocorticoid receptor. Using a glucocorticoid 10-50-fold more potent than dexamethasone, we will compare the binding of 3H cortivazol to lymphocytes and lymphocyte cytosol in depressed subjects with hypercortisolemia, in patients with schizophrenia, and in normal subjects. In addition, we will biochemically characterize the glucocorticoid receptor in these patient groups by means of sucrose density gradient centrifugation, SDS polyacrylamide gel electrophoresis, and 2-dimensional gel electrophoresis. While the lymphocyte glucocorticoid receptor may not reflect the true status of a central nervous system receptor, evidence that depression is associated with a receptor-mediated defect would be an important breakthrough in understanding the mechanism of the disease. In addition, the presence of glucocorticoid resistance in depressive illness offers a unique opportunity to study the mechanisms of hormone resistance in a large clinical population, as well as a chance to localize abnormalities in the pathway of steroid hormone action.